In medical industry, direct conversion materials, such as Si, GaAs, CdTe, and CZT gain more and more importance in modalities, such as CT detectors, X-ray detectors, Gamma detectors, and nuclear medicine in which the scintillator type detectors are still state of the art. Their advantage over scintillators is the possibility of photon-counting coupled with a good energy solution. However, these direct conversion materials are vulnerable because of charge sharing, a phenomenon in which the charge cloud generated by a single photon is collected by several neighboring electrodes. FIG. 1 shows that a charge cloud generated by one photon is collected by three neighboring electrodes. The phenomenon of charge sharing disturbs the spectral resolution and count rate performance of detectors. In high-rate detectors, the phenomenon of charge sharing limits the effort of adopting smaller pixels. At the same time, the phenomenon of K-escape also limits the adoption of smaller pixel sizes. K-escape is primarily caused by partial transport of the primary energy, e.g. X-ray energy, through another quantum, e.g. an X-ray quantum, to a neighboring pixel.
Thus there is a need to solve or mitigate the negative influence of charge sharing, especially in detectors based on direct conversion materials.